What Are UPS And PDU?

When dealing with system administration and server room organization, it is crucial to distinguish two notions – PDU and PSU. System administrators engaged in the process of data center arranging inevitably face the necessity to feed the system. And both abbreviations are responsible for sufficient and uninterruptible systems feeding with electricity.

What is a Power Supply Unit (PSU)?

PSU is a piece of system apparatus that is used to convert power supplied from a wall outlet into an appropriate form. The procedure is required since computer components can’t function properly if being fed by AC (alternating current). Thus, current must be converted into another, acceptable form, which is DC (direct current). Another important function of this product is that it regulates superheat by controlling the voltage.

How to Choose the Right PSU?

The power is the main parameter when choosing a PSU. The parameter is chosen based on the power consumption of all other server components.

In the long term, it is recommended to take the power supply unit based not only on current needs but also foresee future system expansion. In the case of a system upgrade, many administrators face the situation when the existing PDU is not powerful enough to feed a newly upgraded system. In such cases, a more powerful PSU is required.

Efficiency certificates are the second crucial factor when choosing the device. The indicator specifies the efficiency of the power supply. Products with efficiency certificates range from 80 to 96 percent. The more advanced certification the device has, the higher its efficiency and, accordingly, the more resistant to overheating it is and the quieter cooling system it has.

A non-certified model isn’t necessarily worse than a certified one; they just haven’t passed certification testing. It should be noted that some companies add 85+ and 90+ to the name of their products. This is done as an attempt to mislead a consumer; such certificates do not exist.

What is a PDU (Power Distribution Unit)?

A PDU is required for the proper functioning and management of server rooms. The thing is that diverse devices require different amounts of power to function steadily. In the case of a system reboot (simultaneously started), the system may face the inability to start some equipment if it is not equipped with the regarded product.

A special power strip is the most common form of PDUs. They are connected to routers, servers, and switches housed in server racks and cabinets. They are widely used in data centers since they allow coping with the following tasks:

• regulate and limit voltage;
• access, control, and manage devices remotely;
• provide telemetrically control of temperature, humidity, etc. if a special utility is programmed;
• measure current fixing in remote check logs and saving data on servers.

They distinguish two main types of power distribution units (PDUs). These are metered and switched models. Both of them provide network-grade power distribution. The only difference between the first kind of power distribution unit and the second option is that the latter provides additional opportunities for remote management and monitoring of your devices and outlets.

PDUs can have different connectors, depending on the needs and types of hardware. Note that they are fastened directly to the rack construction and can be mounted both horizontally and vertically. Models of different lengths and widths are found on the modern market.

Note that most PDUs do not have the function of surge protection. Surge protectors are used in server racks to cope with this problem.

PSU VS PDU: What’s the Difference?

PSU stands as a transition link; its importance is difficult to overestimate. The device intakes AC converts it to DC due to a special generator, which allows reducing power to the required level. Further, power is supplied to functioning parts via PDUs.

PDU allows distributing one flow of electrical current between multiple telecommunication devices supplying them with the required feed.

Both components are indispensable for any computing and network system. They work together to provide an operating system with an uninterruptible power supply, which allows avoiding outbreaks and hardware damage. Both devices are required at any large facility to ensure a high level of infrastructure.